Mildly off topic but I was a postman for a few years and the advice you linked to will get you almost all the way. Next time you get a letter that isn't for you put a big circle around the label, then put a cross through the circle. Don't write anything on it, but next time you see the postman give it directly to him/her/them and ask them to put it in with the blind letters. That will work. Probably.